Null Hypothesis:There is no relationship between the appearance of snails (tone of banding or base colour) and their residing location.
Snails have been chosen as the subject of this investigation because that they have several clear and distinguishable phenotypes, as well as there being fewer ethical issues when working with this species, in comparison to working with other organisms such as humans. what about the mapping of genotype onto phenotype, what do we know about that (with references)
To collect the required data, four people were arranged in a straight line a shoulder's width apart and covered 20 metres, taking a belt transect perpendicularly from grassland to shrubs whereby each individual recorded the colour and distance of the snails found. The remaining person was in charge of reporting the distance where snails were found to the nearest 10cm, which would also be recorded by the snail collectors. (refer to figure 1 below for further clarification). This system was implemented twice in two separate valleys.
Sampling in this fashion provides a representative illustration of the change in snail type across varying terrains, allowing us to conclude whether it is genetic flow or gene flow that is existent amongst the snail population. It is expected that a transition from dark snails in the woodland to lighter-coloured snails in the grassland would be visible, and by ensuring that our transect cuts through these two major terrain types, we would be exposed to the full spectrum of contrasting snail types, making phenotypic and further data analysis simpler. If this expectation is found to be true, the idea of gene flow would be supported, since there would a gradual transition of one characteristic through the transect couldn't this pattern be explained without gene flow, if the environment changed in a continuous manner, so all snails were adapted to the local environment? (you may not perceive the important change in the envt, which may look as if it has a sudden change to you), calling for a rejection of the null hypothesis what pattern would be expected under the null?.
You need to explain what patterns are expected under alternative hypotheses, and hence how your observations will distinguish between them. Figure 1 - Devised system of data collection.
Credits to Yasmeen Muhammad, Gizzy Starr, Patrycja Wawrzyniecka, Edward Wilding and Wilson Wong.
Snails have been chosen as the subject of this investigation because that they have several clear and distinguishable phenotypes, as well as there being fewer ethical issues when working with this species, in comparison to working with other organisms such as humans. what about the mapping of genotype onto phenotype, what do we know about that (with references)
To collect the required data, four people were arranged in a straight line a shoulder's width apart and covered 20 metres, taking a belt transect perpendicularly from grassland to shrubs whereby each individual recorded the colour and distance of the snails found. The remaining person was in charge of reporting the distance where snails were found to the nearest 10cm, which would also be recorded by the snail collectors. (refer to figure 1 below for further clarification). This system was implemented twice in two separate valleys.
Sampling in this fashion provides a representative illustration of the change in snail type across varying terrains, allowing us to conclude whether it is genetic flow or gene flow that is existent amongst the snail population. It is expected that a transition from dark snails in the woodland to lighter-coloured snails in the grassland would be visible, and by ensuring that our transect cuts through these two major terrain types, we would be exposed to the full spectrum of contrasting snail types, making phenotypic and further data analysis simpler. If this expectation is found to be true, the idea of gene flow would be supported, since there would a gradual transition of one characteristic through the transect couldn't this pattern be explained without gene flow, if the environment changed in a continuous manner, so all snails were adapted to the local environment? (you may not perceive the important change in the envt, which may look as if it has a sudden change to you), calling for a rejection of the null hypothesis what pattern would be expected under the null?.
You need to explain what patterns are expected under alternative hypotheses, and hence how your observations will distinguish between them.
Figure 1 - Devised system of data collection.
Credits to Yasmeen Muhammad, Gizzy Starr, Patrycja Wawrzyniecka, Edward Wilding and Wilson Wong.